TWI416108B - Quartz sensor and sensing device - Google Patents

Abstract

To provide a quartz sensor capable of detecting a sensing target with high sensitivity also in measurement in a liquid phase in which a difference in Q values at the time of measurement in the liquid phase and in a vapor phase is small. In a quartz sensor 1 including an AT-cut quartz plate 11 having a capture layer (absorbing layer) 12 formed on one surface (XZ' surface) thereof and detecting a sensing target based on an amount of change in a frequency of a quartz resonator 10 caused when the sensing target is absorbed by the capture layer 12, there are formed electrodes 13 for oscillating the quartz plate 11 on end faces (XY' surfaces) mutually opposite in a Z' direction of the surface of the quartz resonator 10 on which the capture layer 12 is formed (XZ' surface).

Description

Quartz sensor and sensing device Field of invention

The present invention relates to a quartz sensor and a sensing device capable of measuring a sensing object with high reliability in a liquid phase.

Background of the invention

As a sensor for sensing and measuring a trace substance, for example, a quartz sensor using a quartz vibration element is used. The quartz sensor is an adsorption layer formed on the surface of the quartz plate. When the surface of the adsorption layer is attached to the sensing object, the natural vibration number of the quartz is changed by the mass addition effect according to the weight of the attached sensing object, and A sensor that measures the concentration of the sensing object using the nature of the change. The adsorption layer uses an antibody such as a protein to carry out antigen adsorption in a sample solution (such as blood) by antigen-antibody reaction (capture by reaction).

As disclosed in Patent Document 1, a quartz vibration element used in the above quartz sensor has a surface of an AT-cut quartz plate and an electrode formed therein, which is called a vertical electric field excitation type quartz vibration element. At this time, the surface side electrode An adsorption layer is formed. In the quartz vibrating element, for example, a 9 MHz quartz vibrating element has a series resistance of about 10 Ω in an equivalent circuit in a gas phase, but in a liquid phase (such as pure water), the series resistance becomes 200 to 300 Ω. about. In the case of the quartz sensor having the quartz vibrating element described above, the series resistance varies depending on the viscosity of the solution, but since the series resistance in the liquid phase is small, the degree of change due to the viscosity of the solution is large, The influence on the resonance frequency change at the time of oscillation causes the reliability of the measurement result to decrease. In order to make the degree of change of the series resistance not affect the resonance frequency or reduce the influence to a negligible degree, the quartz sensor can be constructed such that the series resistance of the quartz vibration element takes a larger value, such as 3 kΩ.

On the other hand, the vertical electric field excitation type quartz vibration element has a Q value in the liquid phase compared with the gas phase (f ₀ /Δf: f ₀ is a resonance frequency, and Δf corresponds to a resonance current on the resonance curve The 1/√2 band of the maximum value (the width of the resonance curve) is low. For example, the Q value in the atmosphere is about 60,000, but the Q value in the water is reduced to about 2000. In general, if the Q value is low, the stability of the quartz vibration element is poor and the electronic noise is large. Therefore, even if a quartz vibration element is used, the measurement in the liquid phase is still a potential problem, and therefore it is expected to ensure higher reliability. Technology.

Prior technical literature Patent literature

Patent Document 1 Special Opening 2006-78181

In view of the foregoing, it is an object of the present invention to provide a quartz sensor and a sensing device which can obtain high reliability when measuring a sensing object in a sample liquid.

The quartz sensor of the present invention is formed on a surface of an AT-cut quartz plate to form a capture layer for capturing a sensing object in the sample liquid, and the quartz plate is obtained by capturing the sensing object on the capture layer. The number of natural vibrations is changed, and the object to be sensed is sensed based on the change, and an electrode for vibrating the quartz plate is provided on the mutually opposite end faces of the quartz plate.

In addition, the quartz sensor is preferably constructed as follows.

1. A metal layer insulated from the electrode is formed on a surface of the quartz plate, and the capturing layer is formed on the metal layer.

2. When the electrode provided on the end face of the quartz plate is used as the first electrode, a second electrode facing each other is provided on each of the two plate faces of the quartz plate, and the first electrode and the second electrode are electrically connected to each other.

3. The first electrode and the second electrode are electrically connected to each other on a quartz plate.

A sensing device according to the present invention includes the quartz sensor, an oscillation circuit connected to the quartz sensor, and a measuring unit for measuring a frequency signal from the oscillation circuit.

According to the present invention, in the quartz sensor using the AT-cut quartz plate, a trap layer is disposed on the surface of the quartz plate, and electrodes are disposed on opposite end faces in the Z' direction of the plate surface to form a balanced electric field excitation type quartz vibration element. Therefore, even if a high Q value can be obtained in the liquid phase, the frequency reliability is high, and high-reliability measurement of the sensing object in the sample liquid can be performed.

Simple illustration

Fig. 1 is a perspective view showing a quartz sensor according to an embodiment of the present invention.

2(a) and 2(b) are a perspective view and a cross-sectional view showing a quartz resonator element incorporated in a quartz sensor according to an embodiment of the present invention.

Fig. 3 is a top view of a printed substrate constituting a part of the aforementioned quartz sensor.

4(a) and 4(b) are a longitudinal sectional view and an enlarged view showing the quartz sensor.

Figure 5 is a top view showing the aforementioned quartz sensor.

Figure 6 is a perspective view showing the sensing device of the present invention.

Fig. 7 is an example of the measurement results measured using the aforementioned quartz sensor.

Fig. 8 is a view showing the configuration of the aforementioned sensing device.

Fig. 9 is a longitudinal sectional view showing a quartz sensor of another embodiment.

Fig. 10 is a perspective view showing a quartz plate of another embodiment.

Fig. 11 is a perspective view showing a quartz sensor of another embodiment.

Fig. 12 is a perspective view showing a quartz plate of another embodiment.

Fig. 13 is a view showing a configuration of a part of a sensing device of another embodiment.

Fig. 14 (a) to (c) are explanatory views for explaining an example of measurement results of the above-described sensing device.

Fig. 15 is a perspective view showing a quartz plate and a quartz sensor of another embodiment.

Fig. 16 is a longitudinal sectional view showing a quartz sensor of another embodiment.

Fig. 17 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 18 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

19(a) and (b) are views showing a quartz plate and a side view of another embodiment.

20(a) and (b) are views showing a quartz plate and a side view of another embodiment.

21(a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 22 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

23(a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 24 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 25 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

Form for implementing the invention

A quartz sensor according to an embodiment of the present invention will be described. As shown in FIG. 1, the quartz sensor has a quartz vibration element 10, a printed circuit board 2, and a cover 3. As shown in Fig. 2, the quartz resonator element 10 is, for example, an AT-cut reed-shaped quartz plate 11 having a long side extending along the X-axis of the quartz and a short side along the Z'-axis of the quartz (the axis of the Z-axis is inclined by 35° 15 ' ) Extension, the thickness direction is the Y' axis of quartz (the axis of the Y axis is inclined by 35° 15 ' ). On one of the plate faces (the upper surface of the second (a): XZ' plane) of the quartz plate 11 of the quartz resonator element 10, the metal layer 11a (see FIG. 2(b)) is formed into a circular shape, and the metal A trap layer (adsorption layer) 12 is formed on the surface of the layer, and the trap layer 12 captures, for example, an antigen as a sensing object by an antigen-antibody reaction. The metal layer 11 (a) is formed by, for example, laminating gold on the upper surface of chromium (Cr) as an adhesion layer. The opposite end faces of the quartz plate 11 in the Z' direction form an electrode 13 for oscillating the quartz plate 11, and the lower end portions of the electrodes 13 are wound around the other side of the quartz plate 11 (Fig. 2(a) The lower side) is connected to a conductive circuit of a printed circuit board to be described later. The metal layer 11a and the electrode 13 are simultaneously formed by, for example, photolithography. Moreover, the water-repellent layer 14 is formed in an annular shape in the outer edge region of the trap layer 12 on the quartz plate 11, that is, a portion facing the lower end portion of the cylindrical body of the cover body to be described later. The water-repellent layer 14 prevents the sample liquid from flowing out from the gap between the water-repellent layer 14 and the lower end portion of the cylindrical body.

As shown in Fig. 3, the printed circuit board 2 is provided with conductive circuits 21a and 21b in parallel from one end side to the other end. Further, on one end side of the conductive circuits 21a and 21b, electrodes 22a and 22b for connecting to electrodes on the spacer side to be described later are formed, and the other end sides of the conductive circuits 21a and 21b have connection terminals for connection to connection terminal portions of an oscillation circuit to be described later. .

As shown in Figs. 1 and 4(a), a square box-shaped cover 3 is provided to cover one end side region of the printed circuit board 2. Here, if both edges extending in the longitudinal direction of the printed substrate are referred to as a left edge and a right edge, respectively, the three sides of the cover 3 are formed along the one end edge, the left edge, and the right edge of the printed circuit board 2, respectively. The reed-like spacers 51a and 51b are provided between the cover 3 and the printed circuit board 2, and the spacers 51a and 51b are made of, for example, resin or rubber, respectively, along the left and right edges. In the quartz vibrating element 10, the electrodes are not provided with the electrodes and are disposed opposite to each other in the X direction so as to straddle the spacer 11 in parallel with the left edge (right edge) of the printed substrate 2, the edge portion and the spacer The contact positions of 51a and 51b are further outside than the liquid storage space of the sample liquid to be described later.

As shown in Fig. 4(a), electrodes (not shown) are formed on the upper and lower surfaces of the spacers 51a and 51b. In order to connect the electrodes to each other, the spacers 51a and 51b are provided with the conductive circuits 52a and 52b in the thickness direction. . The upper surface electrodes of the spacers 51a and 51b are in contact with the lower surface electrode 13 of the quartz resonator element 10 (see FIG. 2(b)), and the lower surface electrodes of the spacers 51a and 51b are respectively connected to the conductive circuit 21a of the printed circuit board 2, The ends (electrodes) 22a, 22b of 21b are in contact. Therefore, when a voltage is applied to the conductive circuits 21a and 21b of the printed circuit board 2, a voltage is applied to the electrodes 13 of the quartz resonator element 10.

As shown in Figs. 4 and 5, the central portion of the cover 3 is opened, and the cylindrical body 31 extends downward from the opening side. The lower edge of the cylindrical body 31 is slightly above the surface of the quartz vibration element 10. The area surrounded by the cylindrical body 31 and the surface of the quartz resonator element 10 constitutes a liquid accommodating space 32 for accommodating the sample liquid. Further, the cylindrical body 31 is made of a water-repellent material, and the water-repellent layer 14 formed on the surface of the quartz plate 11 rebounds the sample liquid, and the surface tension thereof prevents the sample liquid from passing through the cylindrical body from the accommodating space 32. A gap between the lower edge of 31 and the surface of the quartz resonator element 10 leaks outward (refer to Fig. 4(b)).

Next, the sensing device 6 will be described. As shown in Fig. 6, the sensing device 6 includes the quartz resonator element 1, an oscillating circuit unit 4 including a detachable oscillating circuit mounted on the quartz vibration element, and a sensor body 61 and, for example, an individual. The measurement unit of the computer 62. The quartz sensor 1 is a terminal portion (guide circuit) 21a, 21b of the printed circuit board 2, which is connected to the terminal portion 49 of the oscillating circuit unit 4, and the oscillating circuit unit 4 is electrically connected to the sensor main body 61 via, for example, a coaxial cable. The oscillation circuit in the oscillation circuit unit 4 is configured as a Kirz-type oscillation circuit unit, and has a function of oscillating the quartz vibration element 10 of the quartz sensor 1. In Fig. 8, Tr is a transistor which is an oscillation amplifying element, 40 and 41 are capacitors of divided capacitive components, and Vcc is a constant voltage source. For other parts, 42 to 44 are capacitors, and 45 to 48 are resistors. The sensor main body 61 is connected to the rear stage of the oscillation circuit unit 4 through the buffer amplifier 63. The aforementioned sensor body 61 has a function of measuring a signal related to the oscillation output frequency of the oscillation circuit unit 4. The frequency measurement method may use a frequency counter or a quadrature detection frequency signal, and calculate a rotation vector rotated by a frequency of the frequency signal and a frequency difference between the frequencies of the detected frequency signals, and the phase of the rotation vector The change is evaluated as the speed of the rotation vector to find the speed.

Next, the step of measuring the object to be sensed (for example, the concentration of an antigen in blood or serum) using the quartz sensor 1 and the sensing device 6 having the above-described configuration will be described. First, the quartz sensor 1 is inserted into the socket of the oscillation circuit unit 4 of the sensing device 6, and the terminal portions (guide circuits) 21a, 21b of the printed substrate 2 and the terminal portions 49 of the oscillation circuit unit 4 are electrically connected by the insertion. . Next, the quartz vibration element 10 is oscillated by the oscillation circuit unit 4, and the oscillated frequency signal is input to the sensor main body 61. Then, the measurer injects, for example, saline into the opening of the cover 3 of the quartz sensor 1 as a diluent, so that the liquid storage space 32 is filled with the saline solution, and the environment of the quartz resonator element 10 changes from the gas phase to the liquid phase, and the measurement is performed at this time. The frequency. Next, the sample liquid which has been kept in the original state or diluted with, for example, saline, is injected into the liquid storage space 32 of the quartz sensor 1 from the opening, and an antigen-antibody is generated depending on the antigen contained in the sample liquid and the antibody of the adsorption layer. Capture by reaction. As the antigen-antibody reaction proceeds, the frequency value decreases due to the mass loading effect. Then, as shown in Fig. 7, the degree of frequency change of, for example, 74 Hz is obtained in accordance with, for example, the personal computer 62 connected to the sensor main body 61, and the concentration of the sensing object is measured based on, for example, a standard curve prepared in advance.

The lower end portion of the cylindrical body 31 of the cover body 3 may be bent outward to form a flange shape as shown in Fig. 9.

Further, the shape of the metal layer 11a is formed in a rectangular shape, and as shown in Fig. 10, the trap layer 12 may be formed thereon. At this time, as shown in Fig. 11, the opening portion of the cover 3 may be opened to have a rectangular shape, and the square cylindrical body 31 is extended by the opening edge to match the shape of the trap layer 12.

According to the above embodiment, the quartz sensor 11 is an AT-cut quartz plate 11, a trap layer 12 is provided on the surface of the quartz plate 11, and electrodes 13 are disposed on opposite end faces of the plate surface Z' to form a balanced electric field excitation type. Since the quartz resonator element 10 can obtain a high Q value even in a liquid phase, the frequency stability is high, and high-reliability measurement can be performed on the object to be sensed.

Next, a quartz sensor according to another embodiment of the present invention will be described. As shown in Fig. 12, a central portion of the end surface of the quartz plate 11 used in the quartz sensor 1 is formed with a groove portion 100 constituting an elastic boundary layer. According to the groove portion 100, the quartz plate 11 is divided into two parts: a first vibration region ( The left area) 101 and the second vibration area (right area) 102. On the plate surface of the quartz plate 11 of the first vibrating region 101, a block layer 103 composed of an antibody that does not transmit a metal layer and react with a sensing object is formed, and an electrode 13a is formed on each end surface. On the plate surface of the quartz plate 11 of the second vibrating region 102, the metal layer 11a is laminated to form the trap layer 12, and the electrode 13b is formed on each end surface. Further, the electrodes 13a and 13b are wound around the other surface side (lower side) of the quartz plate 11.

Then, the quartz sensor 1 is inserted into the oscillation circuit unit 4, whereby one of the electrodes 13a on the side of the first vibration region 101 is connected to the oscillation circuit 111 while the other electrode 13a is grounded, and one of the sides of the second vibration region 102 is placed. The electrode 13b is connected to the oscillation circuit 112 while the other electrode 13b is grounded.

In the quartz sensor 1, the first vibration region does not change with the change in the object to be sensed, and the oscillation frequency "F0" which varies depending only on the temperature regardless of the concentration of the sample solution can be measured (Fig. 14) (a)) In addition, in the second vibration region, the sample liquid concentration based on the adsorption sensing target and the oscillation frequency "F1" based on the temperature can be measured (Fig. 14 (b)). Further, even when a temperature change occurs around the quartz plate 11, the oscillation frequencies "F0" and "F1" are affected by the temperature change under the same conditions. Therefore, by calculating the difference "F1-F0" of the oscillation frequency, it is possible to obtain a highly reliable measurement result in which the frequency change due to the temperature change is removed ((c) of Fig. 14).

Further, in the quartz sensor according to another embodiment of the present invention, as shown in Fig. 15, a case 201 having an upper opening is provided in one end side region of the printed circuit board 2. Each of the both ends of the casing 201 is provided with a mounting member 202 for placing a quartz plate 11 extending in the width direction of the printed circuit board 2. The quartz resonator element 10 is placed on the mounting member 202 and fixed by, for example, a conductive adhesive, and the end surface on which the electrode 13 is formed is orthogonal to the mounting member 202. The trap layer 12 of the quartz resonator element 10 is formed on the surface of the metal layer separated (insulated) from the electrode 13 on the end surface of the quartz plate 11 in the same manner as in the above embodiment. Further, as shown in Fig. 16, since the conductive members 203a and 203b are formed on the surface of the mounting member 202, the quartz plate 11 can be placed on the mounting member 202, and the electrode 13 wound to the lower surface side of the quartz plate 11 can be wound. It is connected to one end of the conductive circuits 203a and 203b. The other ends of the lead circuits 203a and 203b protrude from the bottom of the case 201, and are respectively connected to the lead circuits 21a and 21b of the printed circuit board 2. In the present embodiment, the end surface of the quartz plate 11 (the surface on which the electrode 13 is formed) and the side surface of the casing 201 have slits, and the liquid accommodation space 204 includes not only the surface of the trap layer 12 on which the quartz plate 11 is formed but also the casing 201. The space also includes a space surrounded by the underside (inside) of the quartz plate 11 and the casing 201.

Other examples of the quartz resonator element are described below. As shown in FIGS. 17 to 20, the trap layer 12 of the quartz resonator element 10 is formed not on the quartz plate 11 via the metal layer, but may be configured to be separated from the electrode on the end surface of the quartz plate 11 as in the previous embodiment. A metal layer is formed on the surface of the quartz plate 11 and laminated thereon. In the example of the seventeenth (a) and (b), the region in which the electrode 311 is formed in the entire width direction of the end surface of the quartz plate 11 and the electrode 311 are formed in the central portion of the end face width direction. The region, and mainly uses the former electrode to vibrate the quartz plate 11, and the latter electrode is used to connect with the external electrode.

In the example of Figs. 18(a) and (b), the electrode 321 is provided at one end side and the other end side of the end surface of the quartz plate 11, and the respective electrodes 321 are wound around the lower surface of the quartz plate 11. In other words, in this example, the electrode groups opposed to each other in the Z' direction of the quartz plate 11 are formed in two groups along the longitudinal direction of the quartz plate 11. At this time, the two electrodes formed on the same end surface of each group of electrodes are connected to, for example, a common conduction circuit. In the examples shown in Figs. 19(a) and (b), the structure of Fig. 17 is applied to the two electrodes formed on the same end surface shown in Fig. 18. Further, the quartz resonator element may be provided with the trap layer 12 on both surfaces of the quartz plate 11, and as an example of the configuration of Fig. 19, Fig. 20 is shown.

Further, in the examples shown in Figs. 21 to 24, electrodes are provided not only on the end faces of the quartz plate 11, but also on the left and right edges of the plate surface (upper surface), even under the quartz plate 11 along the left and right edges. Set the electrodes. In these examples, the trap layer 12 is disposed on the entire surface of the quartz plate 11 and is disposed on the electrodes 341a, 341b (351a, 352a) formed on the surface of the board, and thus can be obtained from the conductive circuit, and the parallel electric field is excited. A frequency signal in which the generated frequency signal overlaps with the frequency signal generated by the vertical electric field excitation. Therefore, the frequency signal can be detected with higher sensitivity. Here, in the examples of Figs. 21 and 22, the size of the upper electrode of the quartz plate 11 and the size of the lower electrode are different from each other, that is, the electrode group which generates the vertical electric field excitation is asymmetric. On the other hand, in the examples of Figs. 23 and 24, the size of the upper electrode of the quartz plate 11 is the same as the size of the lower electrode, that is, the electrode group which generates the vertical electric field excitation is symmetrical. Further, the 21st to 23rd drawings are examples in which the capturing layer 12 is provided on one surface side of the quartz plate 11, and the 24th drawing is an example in which the capturing layer 12 is provided on both surfaces of the quartz plate.

An electrode structure that generates not only parallel electric field excitation but also vertical electric field excitation can be applied to the embodiment shown in FIG. 2 or FIG. 12, but the vertical electric field excitation degree is large and the Q value is low, so it is preferable to set a vertical electric field in order to ensure a high Q value. The degree of motivation. As shown in Fig. 25, on both sides of the quartz plate 11, the electrode 361 which is continuous with the end surface of the quartz plate 11 is formed only on the left and right edges, and the trap layer 12 is formed on the electrode on the upper surface side of the quartz plate 11 of these electrodes 361. A metal layer 11a separated from the electrode 361 on the end surface side is formed on the upper surface side of the quartz plate 11 to form the trap layer 12 on the metal layer 11a.

Next, a measurement experiment of the quartz sensor of the embodiment of the present invention was carried out.

experimental method

The quartz sensor used in the experiment is three kinds of quartz vibrating elements according to the 18th, 20th, and 23th embodiments described in the embodiment, and is subjected to quartz in the atmosphere and in phosphate buffered saline (PBS: Phosphate buffered saline). Determination of the equivalent circuit constant of the sensor (series resistance R, inductance L, capacitance C and Q value).

The measurement results

The results of the measurements are shown in the table below. Table 1 shows that the quartz vibration element of Fig. 18 is used for a quartz sensor, Table 2 shows that the quartz vibration element of Fig. 20 is used for a quartz sensor, and Table 3 shows that the quartz vibration element of Fig. 23 is used for quartz. The result of the measurement at the time of the sensor. Further, the frequency difference in the measurement environment from the gas phase to the liquid phase is 131 Hz in the quartz resonator element of Fig. 18, 132 Hz in the quartz resonator element in Fig. 20, and 64 in the quartz resonator element in Fig. 23 Hz.

Inspection

Figures 18, 20, and 23 show that the series resistance (R) varies little regardless of the quartz vibration element. It is known that the series resistance of the quartz vibration element is so large that the change can be ignored. Further, even if the Q value is substantially the same as that in the PBS, it is found that the frequency stability is high even in the liquid phase, and the object to be sensed can be detected with high precision.

1. . . Quartz sensor

2. . . Printed substrate

3. . . Cover

4. . . Oscillating circuit device

6. . . Sensing device

10. . . Quartz vibrating element

11. . . Quartz plate

11a. . . Metal layer

12. . . Capture layer

13. . . electrode

13a, b. . . electrode

14. . . Water layer

21a, b. . . Guide circuit

22a, b. . . electrode

31. . . Cylinder

32. . . Liquid holding space

40~44. . . capacitance

45~48. . . resistance

49. . . Terminal part

51a, b. . . Spacer

52a, b. . . Guide circuit

61. . . Sensor body

62. . . personal computer

63. . . Buffer amplifier

100. . . Ditch

101. . . First vibration zone

102. . . Second vibration zone

103. . . Block layer

111, 112. . . Oscillation circuit

201. . . Box

202. . . Mounting member

203a, b. . . Guide circuit

204. . . Liquid holding space

311. . . electrode

321. . . electrode

341a, b. . . electrode

351a, b. . . electrode

361. . . electrode

Fig. 1 is a perspective view showing a quartz sensor according to an embodiment of the present invention.

2(a) and 2(b) are a perspective view and a cross-sectional view showing a quartz resonator element incorporated in a quartz sensor according to an embodiment of the present invention.

Fig. 3 is a top view of a printed substrate constituting a part of the aforementioned quartz sensor.

4(a) and 4(b) are a longitudinal sectional view and an enlarged view showing the quartz sensor.

Figure 5 is a top view showing the aforementioned quartz sensor.

Figure 6 is a perspective view showing the sensing device of the present invention.

Fig. 7 is an example of the measurement results measured using the aforementioned quartz sensor.

Fig. 8 is a view showing the configuration of the aforementioned sensing device.

Fig. 9 is a longitudinal sectional view showing a quartz sensor of another embodiment.

Fig. 10 is a perspective view showing a quartz plate of another embodiment.

Fig. 11 is a perspective view showing a quartz sensor of another embodiment.

Fig. 12 is a perspective view showing a quartz plate of another embodiment.

Fig. 13 is a view showing a configuration of a part of a sensing device of another embodiment.

Fig. 14 (a) to (c) are explanatory views for explaining an example of measurement results of the above-described sensing device.

Fig. 15 is a perspective view showing a quartz plate and a quartz sensor of another embodiment.

Fig. 16 is a longitudinal sectional view showing a quartz sensor of another embodiment.

Fig. 17 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 18 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

19(a) and (b) are views showing a quartz plate and a side view of another embodiment.

20(a) and (b) are views showing a quartz plate and a side view of another embodiment.

21(a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 22 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

23(a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 24 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

Fig. 25 (a) and (b) are views showing a quartz plate and a side view of another embodiment.

10. . . Quartz vibrating element

11. . . Quartz plate

11a. . . Metal layer

12. . . Capture layer

13. . . electrode

14. . . Water layer

Claims (5)

A quartz sensor is formed on an AT-cut quartz plate surface to form a capture layer for capturing a sensing object in a sample liquid, and the natural vibration of the quartz plate is caused by the capture layer capturing the sensing object The number of changes, and sensing the object to be sensed according to the change, is characterized in that an electrode for vibrating the quartz plate is provided on opposite end faces of the quartz plate. A quartz sensor according to claim 1, which is formed on the surface of the quartz plate to form a metal layer insulated from the electrode, and the trap layer is formed on the metal layer. The quartz sensor according to claim 1, wherein when the electrode provided on the end surface of the quartz plate is used as the first electrode, the second electrode facing each other is provided on each of the two plate faces of the quartz plate, and the foregoing The first electrode and the second electrode are electrically connected to each other. The quartz sensor according to claim 3, wherein the first electrode and the second electrode are electrically connected to each other on a quartz plate. A sensing device comprising: a quartz sensor according to claim 1; an oscillation circuit connected to the quartz sensor; and a measuring unit for measuring a frequency signal from the oscillation circuit.